As stated, the applicant has filed applications for patent which are related to this invention in that they are similarly directed to explosion suppression devices. This invention includes a polarity reversing device described and claimed in U.S. Pat. No. 4,022,131 to Robert J. Redding, issued May 10, 1977 entitled Electrically Operated Release Apparatus. Applicant is a licensee under this patent and the circuit thereof is used in this disclosure.
Previously cited and recognized U.S. Patents include patents to De Boer, U.S. Pat. No. 3,896,881, Bagno et al, U.S. Pat. No. 2,867,282, Gillis et al U.S. Pat. No. 4,487,266, Williams, U.S. Pat. No. 4,281,717, Thery et al, U.S. Pat. No. 4,194,572, McCulloch, U.S. Pat. No. 3,741,309, Mathisen, U.S. Pat. No. 2,783,845, Bentley et al, U.S. Pat. No. 4,356,868, Ferren et al, U.S. Pat. No. 4,815,694, Rozniecki, U.S. Pat. No. 4,889,189, Horner et al, U.S. Pat. No. 3,091,365, Calcaro, U.S. Pat. No. 3,831,682, Hofle et al, U.S. Pat. No. 4,248,309 and Zenker, U.S. Pat. No. 3,971,443. Although all of these patents relate in some manner to fire control apparatus, none of them provide a device that would be considered by one skilled in the art as being pertinent to the question of patentability of the applicant's invention.
Applicant's previous devices have incorporated various detonating devices and various valve control devices for the release of propulsion gas which devices react relatively simultaneously to increases in pressure within volumes to be protected, with it being well known that such pressure increases above a defined threshold are positive indication that an explosion and fire are developing within the monitored volumes. The structure of this device has as its main objective to suppress such an explosion and prevent such fire.
With applicant's device as disclosed herein the primary object is carried out through a detonating circuit which is designed for intrinsically safe operation in hazardous environments and which is continually maintained "at the ready" through continuous charging of a capacitor which releases its charge for detonation upon polarity reversal as caused by a switch arranged to be switched by an increase in pressure within the protected volume.
Further with applicant's device the primary objective is carried out through responsive means to open communication with an air or gas supply which supply cooperates with the explosive force of the detonating circuit to propel extinguishant into the protected area with all steps of detonation and propulsion carried out in such rapid response to pressure rise as to extinguish a forming fire ball.
Further with applicant's device the extinguishant is acted upon by a variety of forces to insure complete and thorough dispersal into the protected area. Should the extinguishant, for any reason, become "packed" by settling and vibration, the various forces insure complete breakup thereof for particulate and effective dispersal.
Applicant's device then, as a primary object, is intrinsically safe to eliminate hazards associated with high energy circuits often used to power such equipment and is rapidly responsive to factors indicative of the formation of an explosion so as to prevent the continuous chain of reactions associated with explosions and fires within volumes such as grain elevators and the like.
These and other objects and advantages of the applicant's invention will more fully appear from a consideration of the accompanying drawings and description of the invention.